Heart valves are sometimes damaged by disease or by aging, resulting in problems with the proper functioning of the valve. Heart valve replacement has become a routine surgical procedure for patients suffering from valve dysfunctions. Traditional open surgery inflicts significant patient trauma and discomfort, requires extensive recuperation times, and may result in life-threatening complications.
To address these concerns, efforts have been made to perform cardiac valve replacements using minimally-invasive techniques. In these methods, laparoscopic instruments are employed to make small openings through the patient's ribs to provide access to the heart. While considerable effort has been devoted to such techniques, widespread acceptance has been limited by the clinician's ability to access only certain regions of the heart using laparoscopic instruments.
Still other efforts have been focused upon percutaneous transcatheter (or transluminal) delivery and implantation of replacement cardiac valves to solve the problems presented by traditional open surgery and minimally-invasive surgical methods. In such methods, a stented prosthetic heart valve, of valve prosthesis, is compacted for delivery in a catheter and then advanced, for example through an opening in the femoral artery, and through the descending aorta to the heart, where the valve prosthesis is then deployed in the valve annulus (e.g., the aortic valve annulus).
Various types and configurations of valve prostheses are available for percutaneous valve replacement procedures. In general, valve prosthesis designs attempt to replicate the function of the valve being replaced and thus will include valve leaflet-like structures. Valve prostheses are generally formed by attaching a bioprosthetic valve to a frame made of a wire or a network of wires. Such a stented prosthetic heart valve can be compressed radially to introduce the stented prosthetic heart valve into the body of the patient percutaneously through a catheter. The stented prosthetic heart valve may be deployed by radially expanding it once positioned at the desired treatment site.
Often, the ability to traverse the tortuous vasculature prior to reaching the treatment site is limited by the state of the disease and/or varying anatomical size of the vasculature.
Accordingly, there is a need for valve prostheses and delivery systems for valve prostheses that are sufficiently flexible to navigate tortuous vessel. In particular, there is a need for modular valve prostheses, delivery systems, and methods of guiding and aligning modules of such modular valve prostheses during deployment.